Like Singapore's rolling tempo to enable singair to avoid carrying extra
fuel?
Care to elaborate? Never had anything like that in my ten years there.
Apparently in South African Airways its policy to always carry an alternate
unless the destination has multiple useable non-intersecting runways, or at any other time the crew feels it necessary, no questions asked. Seems pretty
sensible to me.
Absolutely bog standard just about everywhere in Europe, SE Asia, Middle East etc. Trip Fuel + Contingency Fuel + Diversion Fuel + at least 30mins holding fuel at diversion airfield + fuel for an approach and landing, regardless of weather forecast at destination, more may be added, if there is weight/room if fog, TS, BR etc. is forecast. Never go without a diversion and forecast wx. at diversion at ETA must be above Cat 1 minima. If payload too much to allow this then a 're-dispatch' plan may be used, an achievable destination en route is selected but if fuel approaching this destination is sufficient then flight can continue to original scheduled destination, company variations will apply.
At capts. discretion, when approaching one hour to go to destination, which is an airfield with parallel runways, both serviceable, No Sig Wx, and if fuel is dropping below minimum required then the diversion fuel may be used to complete flight to destination, again, company variations apply.
Possibly not in Australia or the USA?